Diffuser



FIG. 1 is a rear view;

FIG. 2 is a top plan view;

FIG. 3 is a front view;

FIG. 4 is a bottom view;

FIG. 5 is a left side view;

FIG. 6 is a right side view; and,

FIG. 7 is a front perspective view.

The portions of the article shown in broken lines form no part of the design. 

CLAIM The ornamental design for a diffuser, as shown. 